[ERROR] [p.KNXnet/IP Tunneling10.0.0.24:3671] - close connection - maximum send attempts


I’m receiving this ERROR after a while that the system is working correctly (OH2.3 over RPi3). After getting this ERROR, the system stops sending the commands to the KNX. I can see in the GUI all the switches, however, their states are wrong and sending commands through the GUI ending with no real command to the actuators.
I have noticed that the only way to overcome this problem is to delete the log file and to reboot the system.

Prior to this ERROR I’m getting related warnings (many of them):

[WARN ] [p.KNXnet/IP Tunneling] - response timeout waiting for confirmation

My knx/IP gateway can work only in tunnel mode (WEINZIERL771)

I saw that there are some similar issues but no solutions (yet)

Any help will be appreciated


Well, I’m pretty sure, if you have to delete the logs, you have an issue with free space of your file system. What’s the output of

df -h


free -h


sudo du /* -hs

if openHAB is failing?
You could build a bash script to cleanup logs, but as said, I’m pretty sure this is not your main problem.
How many addons do you use?

df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/root        15G  2.1G   12G  15% /
devtmpfs        481M     0  481M   0% /dev
tmpfs           486M     0  486M   0% /dev/shm
tmpfs           486M  6.8M  479M   2% /run
tmpfs           5.0M  4.0K  5.0M   1% /run/lock
tmpfs           486M     0  486M   0% /sys/fs/cgroup
/dev/mmcblk0p1   41M   21M   20M  52% /boot
free -h
             total       used       free     shared    buffers     cached
Mem:          970M       589M       381M       7.4M        48M       274M
-/+ buffers/cache:       265M       705M
Swap:          99M         0B        99Mnd
sudo du /* -hs
du: cannot access ‘/proc/12427/task/12427/fd/3’: No such file or directory
du: cannot access ‘/proc/12427/task/12427/fdinfo/3’: No such file or directory
du: cannot access ‘/proc/12427/fd/3’: No such file or directory
du: cannot access ‘/proc/12427/fdinfo/3’: No such file or directory

Regarding the addons I’m using the following:

  • MapD
  • Basic UI
  • HABPanel
  • PaperUI
  • KNX Binding
  • Astro Binding
  • MQTT Binding
  • OpenHAB Cloud Connector

The size of the openhab.log was ~11.5MB but some times it is larger and same time it is smaller

Well, that’s ok, no problem with filesystem or RAM then :frowning:

have you found a solution to this issue?
I’m facing the same problem with OH3 (same also with OH2 and KNX binding v2, as described here openHAB 2 and KNX binding (no confirmation reply received for L-Data.req...))
I’m using the same WEINZIERL KNX IP BAOS 771

As a first test: don’t set a localSourceAddress.

Thanks @Udo_Hartmann, I already tried in the last two days almost all you suggestions from other posts, always same errors.

Today my BAOS 771 stopped working after an application download, now application is in halted status and I can’t do download anymore, ETS give me an error that say “The device is from a different manufacturer than the application program”.
I wrote to Weinzierl support, in the meantime I decided to buy a mdt SCN-IP100.03 IP Router…